Electrically heated device for antigen tests



pril'7, 1953 R, w, TERRY 2,634,359

ELECTRICALLY HEATED DEVICE FOR ANTIGEN TESTS Filed June 14, 1950 2SHEETS-SHEET l 3 El i- ATTOR N EY April 7, 1953 R. w. TERRY 2,634,359

ELECTRICALLY HEATED DEVICE FOR ANTIGEN TESTS Filed June 14, 1950 2SHEETS-SHEET 2 ninna: 'TnnaJan/.c'ntar' Z A070 d o a 4 's 6 7 a El EE AINVENTOR. Rob erf Wood rzy, ofc-f4 ssa y HS. InQRy, Exc-carR/x ATTORNEYPatented Apr. 7, 1,953

ELECTRICALLY HEATED DEVICE FOR. ANTIGEN TESTS Robert Wood Terry,deceased, late of Columbus, Ghio, by H. Sue Terry, executrix, Columbus,

Ohio

Application June 14, 1950, Serial No. 167,944

Claims. 1

This invention relates to an improved appliance for heatingtest-conducting surfaces, and has particular reference to a portableelectrically heated machine for facilitating the making of blood andserum tests employed in biological determinations. In its more specificaspects, the present invention provides an electrically heated cabinetfor the reception of paper, or other thin sheet materials, containingtest blanks for conducting and recording antigen tests of the typeemployed by hatcherymen for the determination of pullorum disease inpoultry, although the apparatus is applicable to the making ofcontagious abortion tests in cattle, and in other capacities where bloodor serum undergoing tests is deposited on sheets or testing surfaces andadmixed with an antigen to disclose biological characteristics.

Antigen tests on fowls have been carried out heretofore by employingplates or dishes, sometimes referred to as mirrors. On these plates ormirrors, the blood of each fowl tested is separately mixed with antigenand reactions visually noted to determine the presence of certainagglutinations. A more current practice is to employ paper testingsheets of the type set forth in Patent No. 2,194,131, granted March 19,1940, whereby antigen tests are made directly on appropriate sheets ofpaper, or other correspondingly relatively inexpensive material, so thatsaid sheets, following the making of the tests thereon, may be employedas an enduring or permanent record of the tests.

The present invention is particularly useful in carrying out tests onpaper sheets or other similar surfaces. It has been found that bettercontrol of the reaction conditions is obtainable when such sheets are ata somewhat elevated temperature, such, for example, as a temperaturevarying between 109 and 97 F. As a practical matter, these tests areoften conducted out-ofdoors or in unheated sheds or poultry houses, whenwide temperature ranges exist, from the extreme cold of winter to theheat of summer. Such temperature variations affect the reactionconditions present when making antigen tests of the character underconsideration, often giving rise to false determinations of the tests.

It is, therefore, an object of the present invention to provide acabinet or table on which such paper sheets may be placed to admit ofbiological determinations of reactants deposited on the sheets, andwherein provision is made in the construction of the cabinet to producea uniform heating of test sheets flatly deposited thereon,

whereby to render reaction conditions from a temperature standpoint, andalso from a standpoint of time, relatively uniform for all practicalpurposes.

It is another object of the invention to provide an apparatus of thiskind containing means for holding removably a paper test sheet in astationary flat condition on a table surface while tests are being madeand to use controlled electrically actuated means for heating said tablesurface and a paper test sheet contained thereon to desiredtemperatures.

It is another object of the invention to provide apparatus of this kindwhich is simple in construction, fast and convenient to use and whichmay be heated by electrical energy obtained from standard commercialcircuits.

Other objects and advantages will be apparent during the course of thefollowing description.

In the accompanying drawings, forming a part of this specification, andin which like numerals are employed to designate like parts throughoutthe same:

Fig. 1 is a perspective view of an electrically heated biologicaltest-conducting cabinet formed in accordance with the present invention;

Fig. 2 is a vertical longitudinal sectional view taken through thecabinet on the plane indicated by the line 2-2 of Fig. 1;

Fig. 3 is a vertical transverse sectional view taken through the cabinetat right angles to the plane of the section of Fig. 2, as indicated bythe line 3-3 of Fig. 2;

Fig. 4 is a diagrammatic View of the circuit employed in connection withthe electrical resistor heating element of the cabinet;

Fig. 5 is a plan view of one of the paper test sheets used in connectionwith the cabinet;

Fig. 6 is a perspective view of a blood-gathering loop instrumentemployed in depositing blood or serum on the test sheet of theapparatus.

Referring more particularly to the drawings, the improved heatingcabinet C constituting the present invention embodies a casing I0 whichmay be in the form of a rectangular or cubical casting formed from alightweight metal alloy, such as an alloy of aluminum or magnesium, thecasting embodying a substantially vertical front wall Il, back wall l2,side walls I3, and an open top and bottom. At its top, the casing I0.includes inwardly directed substantially horizontally disposed angesI4, the latter being recessed as at l5 along their inner and uppersurfaces to receive the frame I6 of a horizontally disposed table memberl1, which closes the open Vthe front to the back of the cabinet.

Vconductors are indicated at these conductors, a lead-in wire lidiextends to the bimetallic switch arm i5 oi' a temperature-controllingthermostat switch arm, which carries a contact e?, is movable top of thecasing frame l0. This table member is preferably formed of aheat-conducting material such as aluminum or an alloy thereof. Screws i8may be used in uniting the table member and its frame I6 to the recessedportions of the frame anges lli, so that the table member may bestationarily positioned in connection with the cabinet.

Arising from the table member contiguous to the rear edge of the cabinetare spaced upstanding studs i9 which are adapted to pass throughopenings 2B provided in a paper test sheet 2i. This sheet is held in aflat, taut and stationary condition on the upper surface of the tablemember i1 by a hingedly movable positioning frame 22;

This frame at the rear thereof includes a downturned ange 23 which isjoined with the movable leaves of hinges 2e mounted on the back wall I2of the casing frame. The positioning frame 22 is of approximately thesame width as the paper test sheet, and at its forward end, the frame 22is provided with an angular bar 25, the vertical leg 25 of which, whenthe frame 22 is lowered, covers and protects the depending portion 2 ofthe test sheet which depending portion is present as a result of theincreased length of the test sheet with reference to the width of thetable member when measured from The rear angle vbar v'i8 of the frame isis formed with openings through which the studs i9 project when thepositioning frame is lowered to occupy the -positions disclosed in Figs.l to 3.

Integrally formed with the frame is and projecting inwardly andhorizontally from the lower portions of the walls Ii, i2 and i2 thereofare lugs 29 having` flat under surfaces. Held against these undersurfaces in a secure but removable manner is a bottom panel 3d which isretained in position by threaded base posts 3i, the upper ends of thelatter being provided with reduced threaded Shanks which are threadedinto open ings provided in the lugs 2.

Supported on the top of the panel Bil within the confines of the frameiii is an insulating panel 33, the latter being arranged on thimbles 3dthrough which the Shanks of bolts 35 extend, the threaded upper ends ofthe latter receiving nuts 38, holding the insulating panel in secure butspaced relation on and from the bottom member 38.

'Arranged above the insulating panel 33 is a resistor panel 37 andabovethe resistor panel a heat-deecting sheet metal plate 35, the panel4|, as best shown in Fig. 3. Wrapped around A the resistor panel 3l arethe coils of an electrical resistance unit 52, the operation of which iscontrolled'by apparatus which can be best understood by reference to thewiring diagram depicted in Fig. 4. In this latter figure, currentsupplying From one of The free end or the in response to temperatureiluctuations toward and away from a fixed contact s3 mountedstationarily in the casing of the thermostat. i

current flows from one ofthe conductors its,

through wireV 'it and thence through'the'switch' heating period.

4 arm i5, contacts 41 and 48, conductor 50 and thence through theresistance coil d2.

There is a time indicator 5I which includes an actuating control 52mounted on top of the frame i0 on the flange lli. By pressing control52, time indicator 5I starts and runs until the end of the predeterminedinterval, which is noted by an audible click produced by the action ofthe timer.

The flange i4 at the right of the casing frame is provided with abracket means 5&1 for the support of a blood withdrawing andmanipulating loop instrument 55. This instrument is of the ordinary typeemployed in withdrawing blood from a bird, the instrument including forthis purpose a handle 56 which carries at one end a needle 51 used inletting a small amount of blood from a fowl. At its opposite end, theinstrument is formed with a loop 5S in which the let blood may begathered and deposited on one of the numbered squares, shown at S, ofthe test sheet 2i. Also formed in the ange is at the right of the casingframe is a well EQ which extends into the interior of the frame. Thiswell is formed to receive a bottle or other receptacle containingantigen. This antigen in regulated quantities is mixed with the blood ofbirds deposited on the squares of the test paper, the antigen containedwithin the receptacle being heated by the coil 42. The time indicator 5iis then operated through actuation of the control Si, the operationresulting in uniform, clear, decisive and readily determined reactionsbetween the blood undergoing testing and the antigen admixed therewith,so that blood containing or not containing infection-causing bodies maybe rapidly determined. The apparatus is light in weight and may bereadily lifted and manipulated when in use. The paper sheets may berapidly substituted for one another, enabling a large number of fowls tobe examined under reliable conditions and in the shortest possible time.

What is claimed is:

1. Apparatus for conducting biological tests comprising: a rigid-walledcase, a table member of heat-conducting material mounted horizontally onthe top of said case and adapted for thereception of a iiexible andremovable test sheet, movable clamping means carried marginally of saidtable member forretaining such a sheet in a nzied heat-receivingposition on said table member, heating means embodying an electricallyenergized heating resistor mounted in said case, said resistor includingan operating circuit, and a thermostatic switch mounted on the underside of said table member for opening and closing said circuit tomaintain said table member at a substantially uniform temperature duringa given 2. Apparatus for conducting biological tests comprising: arigid-walled case, a table member of heat-conducting material mountedhorizontally on the top of said case and adapted for the reception of aflexible and removable test sheet, clamping means for retaining such asheet in a xed position on said table member, heating Ymeans embodyingan electrically energized heating resistor mounted in said case, saidresistor including an operating circuit, a thermostatic switch mountedon the under side of said table member for opening and closing saidcircuit to maintain said table member at a substantially uniformtemperature during a given heating pe riod, and a timing indicatorcarried by said case for indicating the duration of predeterminedobserved heating periods of said 'heating means.'

3. Apparatus for conducting biological tests comprising: a rigid-walledcase, a table member of heat-conducting material mounted horizontally onthe top of said case and adapted for the reception of a ilexible andremovable test sheet, clamping means for retaining such a sheet in a xedand taut heat-receiving position on said table member, heating meansembodying an electrically energized heating resistor mounted in saidcase, said resistor including an operating circuit, a thermostaticswitch mounted on the under side of said table member for opening andclosing said circuit to maintain said table member at a substantiallyuniform temperature during a given heating period, and a manuallyoperated variable timing indicator carried by said case for indicatingthe duration of observed heating periods of said heating means.

4. Apparatus for conducting biological tests comprising: a caseembodying a substantially rectangular frame, a table member ofheat-conducting material positioned horizontally on the top of saidframe, a panel stationarily supported within the connes of said framebelow7 said table member, a heat-liberating electrically energizedresistor carried by said panel, said relsistor including an operatingcircuit, a thermostatically operated switch responsive to thetemperature of said table member for opening and closing said circuitautomatically to maintain the surface of said table member at asubstantially uniform temperature, a manually operated timing indicatordisposed in said circuit for indicating observed operational period ofsaid heating means, and clamping means for maintaining a paper testsheet in taut unwrinkled contact with the upper surface of said tablemember.

5. Apparatus for conducting biological tests comprising: a caseembodying a substantially rectangular frame defining an internal heatingchamber, a table member comprising an imperforate panel ofheat-conducting material positioned horizontally on the top of saidframe and closing the top of said heating chamber, a heating elementsupporting base arranged in said chamber beneath said table member, aheat-liberating electrically energized resistor carried by said base, anoperating circuit for said resistor, means for insulating said resistorfrom said base, a thermostatically operated switch responsive to thetemperature of said table member for opening and closing said circuitautomatically in maintaining said table member at a substantiallyuniform temperature when in operation, and hingedly movable clampingmeans carried by said case, said clamping means having contact with aflexible test sheet disposed in removable heat-receiving relation withthe upper surface of said table member, said clamping means serving tomaintain said test sheet in a taut, unwrinkled contact with said tablemember, whereby to transmit the heat of the latter directly to saidsheet.

H. SUE TERRY,

, Eecutriz of the estate of Robert Wood Terry,

deceased.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,620,351 Hnilo Mar. 8, 19271,839,573 Merrick Jan. 5, 1932 1,955,359 Crossley Apr. 17, 19342,118,305 Hitsman et a1 May 24, 1938 2,194,131 Terry Mar. 19, 19402,410,013 Clark Oct. 29, 1946 2,477,603 Hester Aug. 2, 1949 2,502,220Kaefer et al Mar. 28, 1950

